Revert "vexpress-a9: Set TARGET_EXTRA_CFLAGS to optimise for A9"

This reverts commit cd1b4d12e630556c19c671ed9e6d3eb80263ce1f
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 3637c41..27bf57a 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -37,7 +37,7 @@
 
 # Dual-Core Cortex A9
 TARGET_CPU_SMP := true
-TARGET_EXTRA_CFLAGS += $(call cc-option,-mtune=cortex-a9,$(call cc-option,-mtune=cortex-a8)) $(call cc-option,-mcpu=cortex-a9,$(call cc-option,-mcpu=cortex-a8))
+#TARGET_EXTRA_CFLAGS += -mtune=cortex-a9 -mcpu=cortex-a9
 
 # ARMs gator (DS-5)
 TARGET_USE_GATOR:= true
\ No newline at end of file